Testosterone, Free (includes Total Testosterone), Adult

Effective June 1, 2016 free testosterone testing will now be performed in-house at China Basin Chemistry. Results may change by up to 15% compared to those obtained using the previous method at Quest.

Available Stat?

No

Test code

FTCA

Test group

Testosterone

Performed by

China Basin Chemistry

In House Availability

Test run on Monday and Thursday.

Method

Total testosterone immunoassay, free testosterone calculation

Container type

Red top (Gold top NOT acceptable )

Amount to Collect

2 mL (blood)

Sample type

Serum

Preferred volume

1 mL (serum)

Min. Volume

0.75 mL (serum)

UCSF Rejection Criteria

Collected in Gold top

Processing notes

Refrigerate serum.

Units

pg/mL (free) and ng/dL (total)

Normal range

Testosterone, Total:

Males ≥ 18 years

240-871 ng/dL

Females ≥ 18 years

9-55 ng/dL

Testosterone, Free:

Age

Males

Females

18-69 years

35-155 pg/mL

0.1-6.4 pg/mL

70-89 years

30-135 pg/mL

0.2-3.7 pg/mL

Synonyms

Free testosterone

Stability

Refrigerated for 2 weeks, frozen at -20oC for 3 years.

Turn around times

Test run on Monday and Thursday. Turnaround time 1-5 days

Additional information

Reference ranges adopted from Quest Diagnostics based on correlation studies comparing our method with the Quest method and by in-house testing of 24 normal male and 31 normal female volunteers in the UCSF Laboratory.